Technical Field
The present invention relates to a zwitterionic monomer, a polyzwitterion synthesized from the zwitterionic monomer, a pH-responsive polyzwitterionic acid synthesized from the polyzwitterion, a polyzwitterion/anion and polyzwitterion/dianion synthesized from the polyzwitterionic acid, and the corresponding methods by which each compound and polymer is formed and use of the polyzwitterionic acid as an antiscalant.
Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
The architecture of Butler's cyclopolymers from diallylammonium salts (Butler G B. Cyclopolymerization and cyclocopolymerization. New York: Marcel Dekker; 1992; Kudaibergenov S, et al.; Polymeric betaines: synthesis characterization and application. Adv. Polym Sci 2006; 201:157-224; Singh P K, et al.; Zwitterionic polyelectrolytes: A review. E-Polymers 2007; 030:1-34; Jaeger W, et al.; Synthetic polymers with quaternary nitrogen atoms-Synthesis and structure of the most used type of cationic polyelectrolytes. Prog Polym Sci 2010; 35:511-77—each incorporated herein by reference in its entirety) has been Recognized as the eighth major structural type of synthetic polymers (Butler G B. Cyclopolymerization. J Polym Sci Part A: Polym Chem 2000; 38:3451-3461; McGrew F C. Structure of synthetic high polymers. J Chem Ed. 1958; 35:178-186—each incorporated hereinby reference in its entirety). These ionic polymers have found manifold applications in industrial processes. Use of sulfur dioxide in the cyclopolymerization protocol provides value added diallyl ammonium salts/SO2 copolymers (Ali S A, et al.; Comparative solution properties of cyclocopolymers having cationic, anionic, witterionic and zwitterionic/anionic backbones of similar degree of polymerization. Polymer 2012; 53:3368-3377; Abu-Thabit N.Y., et al.; Phosphonobetaine/sulfur dioxide copolymer by Butler's cyclopolymerization process. Eur Polym J 2011; 47:1113-23; Ali S A, et al.; Synthesis and comparative solution properties of single-, twin, and triple-tailed associating ionic polymers based on diallylammonium salts. J Polym Sci Part A Polym Chem 2006; 44:5480 94; Umar Y, et al.; The effects of charge densities on the associative properties of a pH responsive hydrophobically modified sulfobetaine/sulfur dioxide terpolymer. Polymer 2005; 46:10709-17—each incorporated herein by reference in its entirety). The nitrogen center in the repeat unit may bear a positive charge as in cationic polyelectrolytes (+). Alternately, the nitrogen center may act as the cationic part of a polyzwitterion (±) containing carboxylate, phosphonate or sulfonate as the negative centers or be the cationic part of a polyampholyte (+−) having a polymer chain containing equal or unequal amounts of opposite charges (Abu-Thabit, N.Y., Al-Muallem H A, Ali S A. The pH-responsive Cycloterpolymers of Diallyl dimethyl ammonium chloride, 3(N,N-Diallylammonio)propanesulfonate, and Sulfur dioxide. J Appl Polym Sci 2011; 120:3662-73—incorporated herein by reference in its entirety). Strong intragroup, intra- and interchain electrostatic dipole-dipole attractions among the dipolar motifs in polyzwitterions (PZs) lead to a collapsed or globular conformation which can undergo a globule-to-coil transition (“antipolyelectrolyte” effect) in salt (e.g. NaCl) solutions owing to the disruption of the network of ionic cross-links (Wielema T A, et al.; Zwitterionic polymers—I Synthesis of a novel series of poly(vinylsulphobetaines). Effect of structure of polymer on solubility in water. Eur Polym J 1987; 23:947-50; Salamone J C, et al.; Aqueous solution properties of a poly(vinyl imidazolium sulphobetaine. Polymer 1978; 19:1157-62; Dobrynin A V, et al.; Flory Theory of a Polyampholyte Chain. J Phys II 1995; 5: 677-95; Higgs P G, et al.; Theory of Polyampholyte Solutions. J Chem Phys 1991; 94:1543-54—each incorporated herein by reference in its entirety). More effective screening of the positive centers in a (±) PZ by Cl-ions as compared to the screening of the negative charges by Na+ ions results in each dipolar zwitterionic motif having a net negative charge, repulsion among which leads to chain expansion (Corpart J, Candau F. Aqueous solution properties of ampholytic copolymers prepared in microemulsions. Macromolecules 1993; 26:1333-1343; Skouri M, et al.; Conformation of neutral polyampholyte chains in salt solutions: a light scattering study. Macromolecules 1994; 27:69-6—each incorporated herein by reference in its entirety). PZs can serve as an excellent polar host matrix owing to their high dipole moments (Yoshizawa M, et al.; Molecular brush having molten salt domain for fast ion conduction. Chem. Lett. 1999; 889-90—incorporated herein by reference in its entirety). The pH-responsive biomimic PZs have been utilized in various fields including: medical (Chan G Y N, et al.; Approaches to improving the biocompatibility of porous perfluoropolyethers for ophthalmic applications. Biomaterials 2006; 27:1287-95—incorporated herein by reference in its entirety), nanotechnology tools (You Ye-Zi, et al.; Directly growing ionic polymers on multi-walled carbon nanotubes via surface RAFT polymerization. Nanotechnology. 2006; 17:2350-4—incorporated herein by reference in its entirety), cosmetics and pharmaceuticals (Kudaibergenov, S E. Polyampholytes: Synthesis, Characterization, and Application. Plenum Corporation; New York: 2002; Salamone J C, et al.; In: Encycl Polym Sci Eng. Mark, H F, Bikales N M, Overberger, C G, Menges G, Kroschwitz H. Eds.; John Wiley & Sons, Inc: New York; 1987: 11, 514-30; Mumick P S, Welch P M, Salazar L C, McCormick C L. Water-soluble copolymers. 56. Structure and solvation effects of polyampholytes in drag reduction. Macromolecules 1994; 27:323-31—each incorporated herein by reference in its entirety), procedures for DNA assay (Filippini D, et al.; Computer screen photo-assisted detection of complementary DNA strands using a luminescent zwitterionic polythiophene derivative. Sensors and Actuators B. 2006; 113:410-8—incorporated herein by reference in its entirety), chelation of toxic trace metals (Ni, Cu, Cd, and Hg) in wastewater treatment, drilling-mud additives (Zhang L M, et al.; New water-soluble ampholytic polysaccharides for oilfield drilling treatment: a preliminary study. Carbohydr Polym 2001; 44:255-260—incorporated herein by reference in its entirety), and water in oil emulsions (Didukh A G, et al.; Oil Gas 2004; 4:64-75—incorporated herein by reference in its entirety).
When the monomer which represents repeating units of the polymer contains an ammonium group and a matching anionic group, it belongs to the betaine family and the charges form an inner salt. A distinctive feature of the polymers of the invention is that they are electrically neutral polymers even though the betaine groups have both positive and negative charges. The positive charge is provided by a quaternary ammonium function, and the negative charge is provided by a sulfonate (sulfobetaines) or phosphonate (phosphobetaines) group.
Some copolymers were obtained by copolymerization of acrylamide with carboxybetaine type monomers. Their properties in solution greatly depend on the pH value and they are incompatible with the desired properties. In fact, at a low pH value, the protonation of the carboxylate functions leads to the loss of the zwitterionic character and the copolymer behaves like a cationic polyelectrolyte, thus sensitive to the presence of salt in particular.
The polybetaines described here have the advantage of keeping their zwitterionic character within a wide pH range. Certain acrylaride and sulfobetaine copolymers have already been described, but they result from synthesis processes carried out in the presence of salts, which is of notable importance for the structures obtained.